zyadz2000 / chip-8-emulator

A simple Chip 8 Emulator written in C++

Chip 8 Emulator

This is a simple Chip 8 emulator written in C++. CHIP-8 is an interpreted programming language, developed by Joseph Weisbecker. It was initially used on the COSMAC VIP and Telmac 1800 8-bit microcomputers in the mid-1970s. CHIP-8 programs are run on a CHIP-8 virtual machine. It was made to allow video games to be more easily programmed for said computers.

This article on Wikipedia explains the virtual machine(CPU,memory,display and keypad) and the opcodes supported.

Screenshots

PONG2

BRIX

Building

Cmake and SDL2 are required for this project. You can install them on Ubuntu using

$ sudo apt-get install cmake libsdl2-dev

For compilation

$ cd cmake-build-debug
$ cmake ..
$ make

The executable file, Chip8_Emulator, will be in the cmake-build-debug folder

Running

You need to provide the path to a ROM file as an argument. 23 ROMS have already been provided in the "roms" directory (downloaded from https://www.zophar.net/pdroms/chip8/chip-8-games-pack.html).

So you can start the PONG game available in the roms directory by

./Chip8_Emulator ../roms/PONG

Test

To run tests

cd cmake-build-debug
make tests
./tests

Catch testing framework is used. More tests need to be added, so PRs are welcome.

Modes

There are two modes available - trace mode and single step mode. You can also type -help to check usage

• Trace mode - Type -t to print the program counter, register values and opcode executed each cycle. It follows this pattern:

  pc opcode I sp V0 to VF

• Single step mode - Type -s flag to execute one instruction at a time waiting for you to press enter after each cycle.

Both modes can be used simultaneously.

Keypad

The original Chip 8 had a hexadecimal keypad (0 - 9 and A - F). The key mapping here is as follows -

Chip 8 Key	Keyboard Key
1	1
2	2
3	3
4	Q
5	W
6	E
7	A
8	S
9	D
0	X
A	Z
B	C
C	4
D	R
E	F
F	V

License

This project is licensed under the GPLv3+. The file LICENSE includes the full license text.